In existing communication networks, such as IP (Internet Protocol) based networks, when a faulty node in a communication path becomes operational again, it is not possible to restore the original communication path without effecting service to the customer. Thus, for example, assume that data is being transferred from source node A to destination node C via one or more intermediate nodes B. Further assume that one of the nodes, say node B, becomes faulty. When node B becomes non-operational, nodes A and C might time out node B and remove all references and connections to node B. An alternative communication path between nodes A and C that does not include node B is established.
In existing networks when node B becomes operational again it is not possible, without effecting service to the customer, to restore the communication path so that node A starts sending data to node C via node B. Thus, a desired Quality of Service (QoS), for example as specified in a Service Level Agreement (SLA) or a Service Level Specification (SLS) between the service provider and the customer is not maintained.